They mustered Gwynedd and set out for Ardudwy. Gwydion set out in the forefront and made for Mur Castell. Blodeuedd heard that they were coming and took her maidens and made for a court on the mountain. But a dense mountain fog came down upon them so that they could not find their way along the road. Then they came by surprise upon a lake, and were all drowned save one maiden alone. And Gwydion overtook her too, and she told him how they were fleeing in haste and then came upon a lake, in which Blodeuedd and all her maidens were drowned, for she was behind and heard the commotion in the water ahead. For this reason the lake is now called Llyn y Morynion.
Lleu Llaw Gyffes then came to Mur Castell, and from there he sent envoys. The message he sent was to ask Gronw Bebyr whether he would surrender all that which he had falsely taken from Lleu, or face the assembled armies of Gwynedd.
